[Vou 2 
794 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
In addition, at the end of a complete carbohydrate series there 
were included for each alga the following checks: 
1. 50 ce. distilled water, 10 ec. enzyme diffusion. 
2. 90 ce. distilled water, 10 cc. enzyme diffusion. 
50 ec. distilled water, 10 ec. boiled enzyme diffusion. 
50 ec. distilled water, 10 ec. boiled enzyme diffusion. 
fm co 
Where the enzyme diffusion referred to above actually con- 
tained carbohydrases, it was extremely difficult to render them 
inactive by heating—10 minutes at the boiling point not being 
sufficient in most cases to more than slow down the action. 
This was probably due to the impurities contained, the rela- 
tively large amounts of protein and slime present tending to 
protect the enzymes. Those extracts relatively richer in such 
constituents proved the more difficult to render inactive. The 
expedient was finally adopted of placing the enzyme material 
in the autoclave and bringing the pressure in the latter up to 
15 pounds. This proved quite effective. 
THE CARBOHYDRASES OF ULVA LACTUCA 
The effect of an extract of Ulva lactuca on different starches. 
—Since starches were to be used in many of the following 
TABLE II 
THE ACTION OF ULVA LACTUCA “DIFFUSION-EXTRACT'* UPON CERTAIN STARCHES 
30 days 
Starch Sugar as 
50 ce. | 
1 per cent BrCese Iodine test 
P in 5 cc. 
mgms. 
Rotatos-oceseeer Blue, trace red 17.4 Complete hydrolysis 
Arrowroot......... Blue, trace red 16.9 Complete hydrolysis 
Wiheats.c eerie: Blue, trace red alfa at Complete hydrolysis 
Gori Wiyssits scores 10.8 Reddish purple 
Solublesseoc00oent 15.9 Traces dextrin 
Reco troree Aes ‘Trace t¢|.e eee eee 
* Wherever the term “diffusion-extract” is employed, it refers to a diffusion 
in water of the alcohol precipitate from an aqueous extract of the alga under 
discussion. 
+ The sugar values in this and the following tables are net, i. e., sugar values 
for all checks have been deducted. 
{In all the following experiments an amount of sugar below 2 mgms. is 
designated a “trace.” 
